I have worked on simplifying the face shield into a 2D, stackable shape, so more manufacturers can produce them using various manufacturing processes, material efficiently and quickly for frontline and care homes during the Covid-19 pandemic. The white part is suitable for machining with 3mm (or 1/8th") end mill (≈1min), laser cutting(<1min), 3D printing with 0.8 nozzle(<20 min) and for injection molding (a draft angle needs to be added).
This face shield is designed to help protect the user but still, please be very cautious and use it at your own risk. This face shield is experimental and hasn’t been approved/disapproved by any authorities, yet. Don't forget that homemade face shields are to be used as last resorts.